Use libc wcwidth to calculate print width in display (#66214)

* Use libc wcwidth to calculate print width in display. Fixes #63105

* Remove errantly added blank lines

* Fixes

* Move setlocale, adjust tests to work around py2 oddity with characters following null

* Don't change cli stub

* emojis

* Remove to_text call

* Special accounting for deletions

* Add initialization function, expand tests, ensure fallback to len

* get_text_width requires text, ensure banner deals with it

* Handle setlocale errors

* Move variable decrement

* Remove unused import
This commit is contained in:
Matt Martz 2020-06-22 16:57:01 -05:00 committed by GitHub
parent 26e8c07f32
commit 1fedb95e4b
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4 changed files with 173 additions and 3 deletions

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@ -0,0 +1,3 @@
bugfixes:
- Display - Use wcswidth to calculate printable width of a text string
(https://github.com/ansible/ansible/issues/63105)

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@ -60,11 +60,13 @@ if __name__ == '__main__':
try: # bad ANSIBLE_CONFIG or config options can force ugly stacktrace
import ansible.constants as C
from ansible.utils.display import Display
from ansible.utils.display import Display, initialize_locale
except AnsibleOptionsError as e:
display.error(to_text(e), wrap_text=False)
sys.exit(5)
initialize_locale()
cli = None
me = os.path.basename(sys.argv[0])

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@ -18,6 +18,7 @@
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
import ctypes.util
import errno
import fcntl
import getpass
@ -36,7 +37,7 @@ from termios import TIOCGWINSZ
from ansible import constants as C
from ansible.errors import AnsibleError, AnsibleAssertionError
from ansible.module_utils._text import to_bytes, to_text, to_native
from ansible.module_utils.six import with_metaclass, string_types
from ansible.module_utils.six import with_metaclass, text_type
from ansible.utils.color import stringc
from ansible.utils.singleton import Singleton
from ansible.utils.unsafe_proxy import wrap_var
@ -48,6 +49,100 @@ except NameError:
# Python 3, we already have raw_input
pass
_LIBC = ctypes.cdll.LoadLibrary(ctypes.util.find_library('c'))
# Set argtypes, to avoid segfault if the wrong type is provided,
# restype is assumed to be c_int
_LIBC.wcwidth.argtypes = (ctypes.c_wchar,)
_LIBC.wcswidth.argtypes = (ctypes.c_wchar_p, ctypes.c_int)
# Max for c_int
_MAX_INT = 2 ** (ctypes.sizeof(ctypes.c_int) * 8 - 1) - 1
_LOCALE_INITIALIZED = False
_LOCALE_INITIALIZATION_ERR = None
def initialize_locale():
"""Set the locale to the users default setting
and set ``_LOCALE_INITIALIZED`` to indicate whether
``get_text_width`` may run into trouble
"""
global _LOCALE_INITIALIZED, _LOCALE_INITIALIZATION_ERR
if _LOCALE_INITIALIZED is False:
try:
locale.setlocale(locale.LC_ALL, '')
except locale.Error as e:
_LOCALE_INITIALIZATION_ERR = e
else:
_LOCALE_INITIALIZED = True
def get_text_width(text):
"""Function that utilizes ``wcswidth`` or ``wcwidth`` to determine the
number of columns used to display a text string.
We try first with ``wcswidth``, and fallback to iterating each
character and using wcwidth individually, falling back to a value of 0
for non-printable wide characters
On Py2, this depends on ``locale.setlocale(locale.LC_ALL, '')``,
that in the case of Ansible is done in ``bin/ansible``
"""
if not isinstance(text, text_type):
raise TypeError('get_text_width requires text, not %s' % type(text))
if _LOCALE_INITIALIZATION_ERR:
Display().warning(
'An error occurred while calling ansible.utils.display.initialize_locale '
'(%s). This may result in incorrectly calculated text widths that can '
'cause Display to print incorrect line lengths' % _LOCALE_INITIALIZATION_ERR
)
elif not _LOCALE_INITIALIZED:
Display().warning(
'ansible.utils.display.initialize_locale has not been called, '
'this may result in incorrectly calculated text widths that can '
'cause Display to print incorrect line lengths'
)
try:
width = _LIBC.wcswidth(text, _MAX_INT)
except ctypes.ArgumentError:
width = -1
if width != -1:
return width
width = 0
counter = 0
for c in text:
counter += 1
if c in (u'\x08', u'\x7f', u'\x94', u'\x1b'):
# A few characters result in a subtraction of length:
# BS, DEL, CCH, ESC
# ESC is slightly different in that it's part of an escape sequence, and
# while ESC is non printable, it's part of an escape sequence, which results
# in a single non printable length
width -= 1
counter -= 1
continue
try:
w = _LIBC.wcwidth(c)
except ctypes.ArgumentError:
w = -1
if w == -1:
# -1 signifies a non-printable character
# use 0 here as a best effort
w = 0
width += w
if width == 0 and counter and not _LOCALE_INITIALIZED:
raise EnvironmentError(
'ansible.utils.display.initialize_locale has not been called, '
'and get_text_width could not calculate text width of %r' % text
)
# It doesn't make sense to have a negative printable width
return width if width >= 0 else 0
class FilterBlackList(logging.Filter):
def __init__(self, blacklist):
@ -321,6 +416,8 @@ class Display(with_metaclass(Singleton, object)):
'''
Prints a header-looking line with cowsay or stars with length depending on terminal width (3 minimum)
'''
msg = to_text(msg)
if self.b_cowsay and cows:
try:
self.banner_cowsay(msg)
@ -329,7 +426,10 @@ class Display(with_metaclass(Singleton, object)):
self.warning("somebody cleverly deleted cowsay or something during the PB run. heh.")
msg = msg.strip()
star_len = self.columns - len(msg)
try:
star_len = self.columns - get_text_width(msg)
except EnvironmentError:
star_len = self.columns - len(msg)
if star_len <= 3:
star_len = 3
stars = u"*" * star_len

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@ -0,0 +1,65 @@
# -*- coding: utf-8 -*-
# (c) 2020 Matt Martz <matt@sivel.net>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
from __future__ import absolute_import, division, print_function
__metaclass__ = type
from units.compat.mock import MagicMock
import pytest
from ansible.module_utils.six import PY3
from ansible.utils.display import Display, get_text_width, initialize_locale
def test_get_text_width():
initialize_locale()
assert get_text_width(u'コンニチハ') == 10
assert get_text_width(u'abコcd') == 6
assert get_text_width(u'café') == 4
assert get_text_width(u'four') == 4
assert get_text_width(u'\u001B') == 0
assert get_text_width(u'ab\u0000') == 2
assert get_text_width(u'abコ\u0000') == 4
assert get_text_width(u'🚀🐮') == 4
assert get_text_width(u'\x08') == 0
assert get_text_width(u'\x08\x08') == 0
assert get_text_width(u'ab\x08cd') == 3
assert get_text_width(u'ab\x1bcd') == 3
assert get_text_width(u'ab\x7fcd') == 3
assert get_text_width(u'ab\x94cd') == 3
pytest.raises(TypeError, get_text_width, 1)
pytest.raises(TypeError, get_text_width, b'four')
@pytest.mark.skipif(PY3, reason='Fallback only happens reliably on py2')
def test_get_text_width_no_locale():
pytest.raises(EnvironmentError, get_text_width, u'🚀🐮')
def test_Display_banner_get_text_width(monkeypatch):
initialize_locale()
display = Display()
display_mock = MagicMock()
monkeypatch.setattr(display, 'display', display_mock)
display.banner(u'🚀🐮', color=False, cows=False)
args, kwargs = display_mock.call_args
msg = args[0]
stars = u' %s' % (75 * u'*')
assert msg.endswith(stars)
@pytest.mark.skipif(PY3, reason='Fallback only happens reliably on py2')
def test_Display_banner_get_text_width_fallback(monkeypatch):
display = Display()
display_mock = MagicMock()
monkeypatch.setattr(display, 'display', display_mock)
display.banner(u'🚀🐮', color=False, cows=False)
args, kwargs = display_mock.call_args
msg = args[0]
stars = u' %s' % (77 * u'*')
assert msg.endswith(stars)